Five years ago, young Muslims across the United States began reading and passing along a blurry, photocopied novel called “The Taqwacores,†about imaginary punk rock Muslims in Buffalo. “This book helped me create my identity,†said Naina Syed, 14, a high school freshman in Coventry, Conn. A Muslim born in Pakistan, Naina said she spent hours on the phone listening to her older sister read the novel to her. “When I finally read the book for myself,†she said, “it was an amazing experience.†The novel is “The Catcher in the Rye†for young Muslims, said Carl W. Ernst, a...